1. Field of the Invention
The present invention relates to a sport shoe, particularly a shoe of the type used in cross-country skiing.
2. Description of Prior Art
Sport shoes, such as those of the cross-country type, comprise a sloe, preferably made of molded plastic, on which a flexible vamp is attached. Such shoes or boots are generally tightened around the foot by, for example, passing lace through holes provided in an upper lacing zone which extends along the length of the longitudinal edges of a slit provided in the upper portion of the vamp. This type of shoe firmly holds the front of the foot. However, this is not necessarily true of the heel of the wearer, which is not well maintained. Although this poor heel maintenance is not a major inconvenience during normal walking, it is a major inconvenience when practicing a sport requiring a substantial flexion of the foot, as is the case when practicing cross-country skiing. This inconvenience arises because the edge of the upper surrounding the instep tends to open during flexion of the foot. As a result, snow can enter the boot and there is overheating due to friction, which can be annoying to the skier.
To overcome these disadvantages, a sport shoe has been developed with an elongated tightening element, of adjustable length, extending behind and against the upper and posterior portion of the upper. In addition, the tightening element is inclined, on each side of the shoe, from the top to the bottom of the shoe and from the rear to the front of the shoe, to tighten the upper edge of the upper around the foot of the wearer. Such a shoe is described in French application No. 81 03085 filed by Applicant on Feb. 17, 1981. Although such a shoe makes it possible to improve the maintenance of the heel in the shoe, it does not overcome the inconvenience of having the tightening element on the exterior of the upper, which spoils the aesthetic appearance of the shoe and can, in certain cases, be bothersome.